The quake that lasted up to 45 seconds occurred at 1:51 p.m. local time (1751 GMT), 135 km southwest of U.S. capital Washington D.C., at a depth of six km, the United States Geological Survey ( USGS) reported on its website.

The quake was also felt as far away as Martha’s Vineyard, some 500 miles (800 kilometers) away, off the coast of Massachusetts, where President Barack Obama was playing golf during his vacation.

Earthquakes of magnitude 5.5 to 6 usually cause slight damage to buildings and other structures.

According to U.S. Nuclear Regulatory Commission (NRC), two nuclear reactors were automatically taken off-line near quake site in Virginia. NRC officials are assessing the situation and sending people to inspect the site.